Some teenage girl gets kidnapped by the big evil serial killer or w/e (think a bit like Eve from V for Vendetta) and he keeps her locked away to be his bride.
After a few days, the cliche of her falling in love with him starts. Basically, she quickly becomes a textbook case of Stockholm syndrome and the serial killers like “yass my bride!”
So he lets her out of the basement occasionally and she never runs and does what he tells her, and one day he has a guest and she acts like his fiancée the whole time. So, since she loves him so bad, he gets far more lenient with her.
Then one day the cops kick the door down and she just fucking kicks him in the nuts really hard and runs to them like “so you got the phone video evidence and the voice recordings and X,Y,Z evidence right?”
And then she turns to look at the serial killer bad guy and he’s being arrested and he’s all “I thought you loved me!”
She just groans and goes “Im a fucking psychology student you absolute ass - it’s called Stockholm syndrome, And i fucking faked it, you really think it’d kick in after like 3 days?”
Turns out she’s been gathering evidence to convict him for the past month because she’s boss.
Basically, psychology student who knows her shit for a main character 2k15